IntroductionThe Nepticulidae are a family of about 800 named species of very small moths (wingspan less than 10 mm), of which the larvae make leaf-mines, stem-mines or rarely galls. The family is poorly known from the desert regions in Northern Africa and the Middle East, but relatively well known from Central Asian deserts (Turkmenistan, Uzbekistan, Mongolia), thanks to the work of R. Puplesis and students (summarised in Puplesis, 1994). The family was previously hardly known from the Arabian Peninsula, except for four species, recently described from northern Oman (Puplesis & Diškus, 2003). Here the family is recorded for the first time from the UAE, with seven species, two in Stigmella Schrank, 1802, and five in Acalyptris Meyrick, 1921, of which one is described as new. Except for S. birgittae Gustafsson, 1985, these species are also new for the Arabian Peninsula. Because some of the recorded species are actually rather common and widespread in the desert regions of North Africa and Asia, but virtually unknown in the literature, several unpublished records and synonymies of these species are presented here and they are redescribed. In this way the family Nepticulidae is not only recorded for the first time from the UAE, but also from Libya, Sudan, Egypt, Saudi Arabia and Pakistan. Stigmella omani Puplesis & Diškus, 2003, is synonymised with S. birgittae Gustafsson, 1985, S. ziziphivora Gustafsson, 1985, is synonymised with S. zizyphi Walsingham, 1911. The latter does not occur in the UAE, but is compared with the closely related S. birgittae. Nepticula liochalca Meyrick, 1916, and N. homophaea Meyrick, 1918, are both synonymised with Stigmella xystodes (Meyrick, 1916), all three described from India; this species is here reported new for many countries in the North-African-Asian warm eremic region. In Acalyptris, A. lvovskyi (Puplesis, 1984) is synonymised with the type species A. psammophricta Meyrick, 1921. Acalyptris gielisi is described as new; it is very close to the South African A. lanneivora (Vári, 1955). From a fifth species of Acalyptris, only one female has been collected. It is described, but not named here. The seven recorded species probably only represent a small portion of the actual fauna, which could best be studied additionally by searching for stem- and leaf-mines on potential hostplants. The genera Trifurcula Zeller, 1848, and Ectoedemia Busck, 1907, are also likely to occur here. DNA sequences of several specimens were used in addition to morphological characters for decisions on species identities, in particular for associating males and females. The results of the barcoding gene CO1 are discussed at the end of this chapter.